Method of making cellular blocks



Jan. 11, 1927.

H. s. ASHENHURST METHOD OF MAKING CELLULAR BLOCKS Original Filed Se t: 10. 1924 Patented Jan. 11, 1927.

UNITED STATES 1,613,639 PATENT OFFICE.

HAROLD S. ASHENHUBST, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO INSULEX CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE. jv

METHOD OF MAKING CELLULAR BLOCKS.

Original application filed September 10, 1924, Serial No. 736,892. Divided and this application filed March 3, 1925. Serial No. 12,883.

This application is a division of my copending application, Serial 'Number 736,892, filed September 10, 1924, in which application I have claimed the block produced by the method herein disclosed and claimed.

One of the objects of my invention is to provide a building block that is light in weight, that'will be relatively non-absorbent, and that will have a dense, hard skin on its top surface. The block is composed of materials that will react in the presence of water to evolve a gas and to provide means for retaining the gas in bubble form until the mass sets and hardens in expanded condition so as to be of a cellular character throughout and correspondingly light in weight.

It is one of the objects of my invention to provide a maximum of body strength in the block even though itis light and of cellular form, the production of such strength depending in part on the development of the surface density. This dense skin is produced by breaking down the light andfragile cells at the top surface of the block and forming from such cellular material so broken down a thin layer of non-cellular gypsum. This surface sets very quickly and.

provides a relatively hard and resistant skin within a few minutes after the block is cast.

The same result may be secured by applyiug a thin coat of non-cellular gypsum by any other suitablemethod to the surface after the rising and expansion of themass are complete. The remaining sides of the block are relatively weak, being of cellular formation with many of the cells open at the surface. Such side and bottom surfaces are not so weak, however, as the top surface a ing it will be better understood by reference to the accompanying drawings, in which v Fig. 1 is a perspective View of a mold 66 within which the block may be formed.

51g. 2 is a perspective view of the block, an

Fig. 3 "is a transverse sectional view through the mold and contained block.

In the drawings. I have illustrated a form of mold comprising abottom 10, and side walls 11, 12, which may be hinged to the bottom if desired. Means such as the clasp 13, may be employed to temporarily secure as the mold sides in the position shown.

After the mold has been prepared as shown, I pour therein a mass of plastic material composed 0fgypsum as the major ingredient, in combination with water and 70 certain chemicals such as'disclosed in my Reissue Patent No. 15,952, of November 25, 1924. Following the addition of the water,

a gas is evolved thus causing the mass to expand or rise. Assuming that a correct quantity of the cementitious materialhas been placed in the mold, it will rise above the sides as indicated in dotted lines at 14,

in Fig. 3. As soon as the full expansion has taken place and before the material hasset, the top is levelled either by screeding or troweling to produce the flat plane surface .15. The operation of levelling results in the formation of a dense relatively'hard outer surface or skln composed of non-cellular 5' gvpsum. This is iudlcated at 16, 1n Fig. 2.

The body of the block is cellular throughout and many of the cells are exposed on the sides and bottom of the block. This provides an ideal plaster surface.

After the block has been levelled and the material has become rigid the sides of the mold are separated and the block removed. It may be immediately placed in position 'in a wall, or allowed to dry and be handled W and shipped without danger of breaking.

lVhile I have described my invention as an improved method of producing a block, I wish to have it understood that I donot desire to limit my invention to small blocks mm adapted to be handled for fabricating a floor, .roof, or vertical wall therefrom as distinguished from a large block comprising by itself a complete floor or roof cast in place in a mold permanently or temporarily may be specifically claimed. I have had very good results by the use of a mixture of the following form,-100 pounds of calcined gypsum, 2 ounces of commercial retarder, 3% pounds of a suitable carbonate such as calcium carbonate, and 8 pounds of aluminum sulphate containing its Water of crystalliz'ation, all of such ingredients being to make a mix that is readily stirred and finely ground and thoroughly mixed in a dry state.

In the mixing of the material, care will be exercised to avoid the use of an excess of water, only sufiicient water being added handled. The block will, therefore, have no unusualaflinity for water and the water of the plaster will not be absorbed.

I claim: I i I '1. The method of forming insulating blocks which consists in casting a' plastic mass that will expand and set, allowing the mass to rise, and then dressing down the top surface of the block bya series of scrapingand smoothing operations serving to break down the expanded formation at the surface and servingthereb to provide a relatively dense and tough in:

2. The method of preparing insulating blocks of gypsum as the major ingredient, consisting in providing an open-top mold, then castmgtherein a quantity of the 'material in plastic form, then permitting the mass to expand; then breaking down the cells on the top surface of the expanded material to provide a relatively smooth, dense and tough skin.

3. The method of forming cellular blocks of insulating material, consisting in providing amold, casting therein a quantity of gypsum together withchemicals that, in the presence of water, will react and cause the mass to expand and set in a cellular condition, then allowing the mass to expand, and

then ,before the setting and hardening are complete dressing down the top surface of the material by a scraping and smoothing operation servingto break down the cellular formation at the surface to provide a dense skin.

4. The method of forming insulating blocks which consists in providing a mold,

then casting therein a plastic mass that will expand and" set, allowing the mass to rise above the top of the mold, and then breaking down the cells contained in the material that projects above the mold top and thereby levelling the top and providing a dense, tough, non-cellular top surface. Signed at Chicago, Illinois, this 27th day of February, A. D. 1925.

HAROLD s. ASHENHURST. 

